It's important to note that even though I've been a developer for over 12 years, I learn an entirely new paradigm that makes me feel like a n00b almost every year. For example, this year I'm trying to get familiar with the TensorFlow libraries for deep learning, and a couple of years ago I made a drastic change in my DevOps practices by incorporating Docker. I've been using Angular for years and my next project requires React, which I've never done. Onwards and upwards.
So someone who is just coming into programming at 30+ may be just as well as someone who has been doing it since they were a teenager. Yes it helps to fully understand fundamentals, and it helps you learn new things faster, but honestly learning new things is the name of the game -- I spend a lot of time un-learning things also, and a lot of times being stuck in old thinking keeps you from moving forward.